The PC-D and PC-X were personal computers sold by Siemens between 1982 (PC-X)/1984 (PC-D) and 1986. The PC-D was the first MS-DOS-based PC sold by Siemens, though it was not fully compatible with the IBM PC architecture. It was succeeded by the PCD-2.
Most of the hardware was identical. While the PC-X was equipped with 1 MB of RAM, a hard disk and a MMU, the PC-D came with 128 kB of RAM and a single 5¼″ floppy disk drive in its basic configuration. More powerful configurations with 256 kB, 512 kB or 1 MB and either a second floppy disk drive or a hard disk with a capacity of 13 or 20 MB were also available. The keyboard layout differed between the two models.
The PC-D had a certain level of compatibility with the IBM PC architecture but differed in a number of aspects:
Intel 80186 processorDouble-density floppy disk drives with a proprietary 80-track format (729,088 bytes)Proprietary monochrome graphics adapter with a resolution of 640×350 pixels and black-on-white text mode (which could be inverted through a software tool)12″ monochrome monitor, powered through the graphics cardV.11 serial ports for keyboard and mouse (the latter being optional)Different keyboard layout: among others, the PC-D had a Help key and keys to control a connected printer but only five cursor keys (←↓↑→ and Home)Both V.11 and V.24 ports for printersA parallel port was available only as an add-on; if not installed, LPT1: and LPT2: would address the serial portsProprietary VG96 Local BusThe power switch could be inhibited in softwareA debug button (located next to the reset button) to display the contents of the processor registersThe mainboard had a SCSI interface, although hard disks had a ST506 interface and were connected to a separate controller board.Optional hardware included:
a two-button mousethe PT20 daisy wheel printer, the PT88 (available as ink jet or pin printer) or the PT89 (the A3 variant of the PT88)the UTC 101, UTC 421-1 or UTC 424-4 teletex controllers, the latter of which could also be used to network up to four PC-Dsa tape drive with a capacity of 45 MBThe PC-D shipped with MS-DOS 2.11 (version 3.20 became available later), which was extended with a menu system through which users could launch applications without having to use the command line. Application software included:
Microsoft WordMicrosoft MultiplanMicrosoft ChartdBase,GW-BASIC interpreter and compilerLotus Spotlight, an application suite which consisted of a notepad, calculator, calendar, card file, phone book and file manager which could be launched on top of other running DOS applicationsOpen Access, an office suite which included a database, a spreadsheet application, a charting tool, a calendar and a BBS terminalA 9750 terminal emulation for BS-2000 mainframe accessSome simple gamesMicrosoft Windows 1.0Hardware calls on the PC-D differed from those on fully IBM compatible PCs, causing most DOS applications to crash on the PC-D unless they were recompiled or patched, making them incompatible with IBM PCs. Windows applications could usually be exchanged between both platforms.
The PC-X shipped with SINIX.
